Most Down Articles

Published in last 1 year| In last 2 years| In last 3 years| All| Most Downloaded in Recent Month | Most Downloaded in Recent Year|

Published in last 1 year

Please wait a minute...


For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails

Select

Review of Key Technologies in New Power System Based on Artificial Intelligence Empowerment DUAN Junfeng, LI Chenkun, YAO Wenxuan, GUO Siyuan Hunan Electric Power    2024, 44 (1): 1-10.   DOI: 10.3969/j.issn.1008-0198.2024.01.001 Abstract （239）      PDF（pc） （5512KB）（412）       Knowledge map    Save Based on the important role of artificial intelligence technology in promoting the intelligence of new power systems, this paper summarizes the current application status, technical challenges, and future development directions of artificial intelligence in new power systems. Firstly,the paper introduce the characteristics and requirements of the new power system. Then, the paper discusses the key application areas of artificial intelligence in new power systems, including the security, stability and control of large power grids, integrated collaborative analysis of source network, load storage, intelligent operation, inspection and management of power systems, as well as active distribution networks and microgrids. Finally, the paper analyzes the technical challenges faced by artificial intelligence in the new power system and proposes relevant suggestions. Reference | Related Articles | Metrics

Select

Capacity Optimization Configuration of Grid-Connected Wind-Solar-Hydrogen-Storage Microgrid ZHAO Na, ZHANG Lian, WANG Shibin, LI Duo, HUANG Wei Hunan Electric Power    2023, 43 (4): 48-55.   DOI: 10.3969/j.issn.1008-0198.2023.04.007 Abstract （79）      PDF（pc） （1469KB）（163）       Knowledge map    Save A single type of energy storage device is difficult to take into account the advantages of multiple types of energy storage devices, while the hybrid energy storage system can integrate the technical and economic advantages of different types of energy storage. Aiming at the optimal configuration of hybrid energy storage based on battery and hydrogen energy storage in grid-connected mode, economic and environmental protection are taken as the objective function, the analytic hierarchy process is used to solve the multi-objective weight problem, and the particle swarm optimization algorithm is used to solve the optimal configuration of microgrid capacity. Different energy storage configuration schemes are analyzed and compared by economy and evaluation index. The results show that the cost of hybrid energy storage is 2.46% and 10.02% lower than that of single battery and hydrogen energy storage. The self-balancing rate is 7.65% and 23.89% higher than that of single battery and hydrogen energy storage, and the redundancy is 19% and 38.16% lower than that of single battery and hydrogen energy storage. Reference | Related Articles | Metrics

Select

Study on Natural Convective Flow Heat Transfer in Supercritical Carbon Dioxide Cavity YE Maojing, WU Tianyu, LIU Kairui, WANG Limin, CHE Defu Hunan Electric Power    2023, 43 (4): 1-8.   DOI: 10.3969/j.issn.1008-0198.2023.04.001 Abstract （86）      PDF（pc） （4176KB）（154）       Knowledge map    Save Horizontal flow of supercritical carbon dioxide (S-CO2) will flow stratification under heating or cooling conditions, resulting in different heat transfer phenomena at the top and bottom of the tube. In order to study the flow heat transfer behavior driven by upward lift in vertical flow direction, the development process of S-CO2 natural convection and the influence of pressure, pipe diameter and temperature interval on the development process are studied based on a two-dimensional circular cavity physical model. The results show that the development process of flow heat transfer away from the pseudo-critical temperature range is relatively stable compared with the pseudo-critical temperature range. In the pseudo-critical temperature range, the higher the pressure, the faster the heat transfer development process. In the pseudo-critical temperature range, the larger the diameter of the pipe, the longer the time for heat transfer to reach stability, and the more intense the main flow zone is in the initial stage of development. Reference | Related Articles | Metrics

Select

Experimental Study on Coal Combustion Catalyzed by Metallic Compounds RAO Hua, XU Huifang, WU Aijun, BIN Yiyuan, DU Wei, CHENG Shan Hunan Electric Power    2023, 43 (5): 85-91.   DOI: 10.3969/j.issn.1008- 0198.2023.05.013 Abstract （19）      PDF（pc） （10252KB）（129）       Knowledge map    Save The combustion experiment of Hunan bituminous coal was carried out under air atmosphere with the final temperature of 1150 ℃ by thermogravimetric analysis.Different proportions of CaO, Fe2O3, NaCl and MgO in coal was adding to explore the influence of metal compounds on the combustion characteristics of coal. The experimental results show that the ignition temperature can be reduced, and the combustion stability can be improved and the combustion efficiency can be improved by adding a certain amount of metal compounds into the pulverized coal. The metal compounds CaO, Fe2O3, NaCl and MgO have different catalytic effects on the combustion of pulverized coal. The addition of NaCl and Fe2O3 makes the combustion of pulverized coal violent, which is conducive to the burnout of pulverized coal. The effect of NaCl on comprehensive catalytic combustion is the best,and the ignition temperature of the sample with NaCl decreases about 22 ℃.The identification index of Cb ,G and Hj increase with the decrease of MgO percentage, and the flammability is better. The addition of CaO and MgO will increase the ignition temperature of pulverized coal, and the combustion stability and burnout effect of pulverized coal will become worse, and the influence of CaO is greater than that of MgO. The catalytic combustion effect is best when the NaCl content is 8%. Reference | Related Articles | Metrics

Select

Analysis and Research on Influence of High Temperature and Dry Weather on Regional Power System in 2022 Summer BIE Fangmei, FANG Rengcun, WAN Jing, FAN Yuhong, CHEN Xi Hunan Electric Power    2023, 43 (4): 108-113.   DOI: 10.3969/j.issn.1008-0198.2023.04.016 Abstract （59）      PDF（pc） （2088KB）（108）       Knowledge map    Save In view of the difficulties and challenges faced by the power system during the extremely hot weather in summer in 2022, taking the operation of typical provincial power grids as an example, the maximum load, peak load duration and summer power grid load characteristics of the whole network are studied, and the outstanding problems in power supply during the summer vacation are analyzed, so as to put forward countermeasures and suggestions for how to ensure the safe and stable operation and reliable supply of the power system in summer. Reference | Related Articles | Metrics

Select

Review of Digital Real Time Hardware-in-Loop Simulation for New Type Power Systems DU Shanzhou, HUANG Yongbo, LU Guoping, GAO Jin, QIN Yuxiang, LIU Yonglu, YUAN Liang Hunan Electric Power    2023, 43 (5): 3-10.   DOI: 10.3969/j.issn.1008- 0198.2023.05.001 Abstract （95）      PDF（pc） （8566KB）（105）       Knowledge map    Save With the increasing proportion of new energy access and the wide application of power electronic equipment, digital real time hardware-in-the-loop simulation has become an important means of simulation analysis of new power systems. In this context, the paper aims to summarize the research status of digital real-time hardware-in-the-loop simulation at home and abroad, and discuss the key technologies for improving simulation efficiency and accuracy as well as the difficulties in the process. This article starts from the development history of digital real-time hardware-in-the-loop simulation, and discusses the component modeling of digital real-time simulation in turn, including Ron/Roff and L/C two types of device modeling methods, summarizes three types of interface circuits of Thevenin equivalent, Norton equivalent and frequency-dependent network equivalent methods, discussed high-speed parallel algorithms, simulation platform architectures based on different computing units and types of hardware-in-the-loop simulation, introduces the basic flow of typical digital real-time hardware-in-loop simulation and its application in new power systems application examples, and finally summarizes the advantages and disadvantages of various architectures and algorithms as well as applicable scenarios. Reference | Related Articles | Metrics

Select

Load Aggregator Strategic Quotation and Peak Market Clearing Optimization Considering Adjustment Cost ZHANG Lingqiao, ZHOU Zhengcheng, SHEN Shasha, XIANG Yunkun, LIU Hanlin, WANG Wei, MENG Ke Hunan Electric Power    2023, 43 (4): 24-31.   DOI: 10.3969/j.issn.1008-0198.2023.04.004 Abstract （49）      PDF（pc） （2676KB）（98）       Knowledge map    Save The access of high proportion of new energy makes the uncertainty of power supply increasing, the unbalance of power supply outstanding and the difference between peak and valley of load increasing. In order to solve the problem of unbalance of power supply and demand during peak hours, a strategic bidding strategy of load aggregator considering adjusting cost and its optimal clearing strategy in peak market are proposed. Firstly, the load aggregator is defined, and the flexible resource is classified according to the characteristics of voltage level, load curve, unit power regulation cost and power consumption characteristics. Secondly,the paper analyzes the characteristics and adjustment potential of various kinds of end-user load, establishes the model of load adjustment cost of various kinds of end-users, and constructs the strategic quotation model, to minimize the sum of load adjustment costs of load aggregators, a clearing model is established. Finally, a typical peak demand response scenario involving a regional load aggregator is taken as an example to demonstrate the validity and scientificity of the proposed method. Reference | Related Articles | Metrics

Select

Transformer Fault Diagnosis Method of Optimized Hybrid Kernel Extreme Learning Machine Based on Improved Northern Goshawk Optimization Algorithm WANG Shibin, LI Duo, ZHAO Na, XIE Wenlong, HUANG Wei, JI Hongyu Hunan Electric Power    2023, 43 (4): 125-132.   DOI: 10.3969/j.issn.1008-0198.2023.04.019 Abstract （97）      PDF（pc） （3096KB）（88）       Knowledge map    Save To improve the accuracy of transformer fault diagnosis, a transformer fault diagnosis method of optimized hybrid kernel extreme learning machine(HKELM)based on improved northern goshawk optimization algorithm(INGO) is proposed. Firstly, the ReliefF algorithm is used to filter and reduce the dimensionality of 19 dimensional transformer fault features. Secondly, three strategies of Logistic tent chaotic mapping, Cauchy mutation operator, and nonlinear increasing weight, are introduced to improve the Northern Hawk optimization algorithm and enhance its global optimization ability. Then, the improved INGO algorithm is used to optimize the initial parameters of HKELM to improve its classification accuracy and robustness. Finally, the features optimized by ReliefF are used as input features for the model and compared with different transformer fault diagnosis models. The simulation results show that the INGO-HKELM fault diagnosis model has higher fault diagnosis accuracy compared to other models. Reference | Related Articles | Metrics

Select

Academician Message CHEN Xiaohong Hunan Electric Power    2024, 44 (1): 0-0.   Abstract （36）      PDF（pc） （4252KB）（88）       Knowledge map    Save Related Articles | Metrics

Select

A New Approach Law Sliding Mode Fault Tolerant Control Method for Double Fed Induction Generator Actuator Fault LI Shengqing, WEN Yanxi, CHEN Xin Hunan Electric Power    2023, 43 (4): 9-15.   DOI: 10.3969/j.issn.1008-0198.2023.04.002 Abstract （62）      PDF（pc） （1809KB）（85）       Knowledge map    Save In order to overcome the gain-bias fault of the actuator during the operation of the double fed induction generator, a second order non-singular fast terminal sliding mode fault tolerant control is designed by combining the PID sliding surface with the nonlinear non-singular terminal sliding mode surface, and by associating the sliding mode surface function with the control gain using a new adaptive reaching law. Then Lyapunov function is used to prove the stability of the controller. The simulation and experimental results show that compared with the traditional PID and the traditional sliding mode control, the proposed control method weakens chattering, improves the response speed by 49.8%, reduces the steady-state error of the system, and has better fault tolerance. Reference | Related Articles | Metrics

Select

Research on Dual Active Bridge Converter and It's Hybrid Modulation for New-Generation Power Systems ZHANG Yiming, XIE Ronghuan, CHEN Xiaoying Hunan Electric Power    2023, 43 (5): 16-22.   DOI: 10.3969/j.issn.1008- 0198.2023.05.003 Abstract （70）      PDF（pc） （16472KB）（81）       Knowledge map    Save The new-generation power systems mainly relies on a high proportion of new energy grid connection. DC transformers is an important energy management unit in new-generation power systems, need to have higher performance and conversion efficiency. In order to reduce current effective value of the DC transformer and improve the control flexibility, this paper proposes a combined dual active bridge converter based on modulated coupled inductor. The proposed converter controls the equivalent inductance of the modulated coupled inductor by modulating pulse-width-modulation signals, without any additional auxiliary circuits. In order to reduce the current effective value of the converter, when the converter operates at light load and the voltage does not match, the coupled inductor can be modulated and controlled to a larger equivalent inductance. When the converter operates at heavy load, the coupled inductor can be modulated and controlled to a smaller equivalent inductance. Meanwhile, a hybrid modulation strategy for the converter is proposed based on the working principle of the modulated coupled inductor, and a minimum current compliance control law is designed. Finally, the proposed converter is validated through experiments, and the results show the effectiveness of the proposed method. Reference | Related Articles | Metrics

Select

Image Classification Method Based on Deep Learning for Inspection Unmanned Aerial Vehiclesin Transmission Line YANG Hongzhao, XI Yanhui, XIANG Sheng, XU Zhikang Hunan Electric Power    2024, 44 (1): 53-58.   DOI: 10.3969/j.issn.1008-0198.2024.01.008 Abstract （58）      PDF（pc） （3904KB）（80）       Knowledge map    Save Due to the irregularity of point cloud data, the classification accuracy of point cloud data feature values is difficult to meet the requirements of transmission line inspection. Therefore,a lidar point cloud classification method based on graph signal processing is proposed. When processing irregular transmission line image signals, the method can directly generate feature values from the original point data, thereby improving classification accuracy. In order to validate the proposed method, the algorithm is validated through physical simulation, and the results show that the classification accuracy in the image could reach 90%. Reference | Related Articles | Metrics

Select

A Condition Estimation Method for DC-link Capacitors Based on Pre-charging Model TIAN Rui, LIU Weike, WU Xun Hunan Electric Power    2023, 43 (4): 133-138.   DOI: 10.3969/j.issn.1008-0198.2023.04.020 Abstract （49）      PDF（pc） （2074KB）（72）       Knowledge map    Save DC-link capacitors are key components for energy buffering in converter systems and are widely used in fields such as locomotive traction, aerospace, wind power generation and photovoltaic power generation. In harsh working environments, the performance of DC-link capacitors deteriorates, the failure rate increases, and they are easily damaged. Currently, the existing methods for state identifying of capacitors are easily affected by sensor measurement noise, resulting in a significant difference between the capacitance identification results and the actual values. To solve these problems, this paper proposes a capacitor state identification method based on the pre-charging process. By constructing the pre-charging model, the mapping relationship between capacitance and voltage signal is obtained, and the influence of measurement noise is minimized. Then, the recursive auxiliary variable least square method is used to estimate the parameters of the pre-charging model, so as to obtain the accurate capacitor capacity identification results. The verification results show that this method can effectively resist the interference of measurement noise, and has good identification effect when the signal sampling frequency is greater than 500 Hz. The capacitance identification error is 0.569% when the sampling frequency reaches 1 kHz. Reference | Related Articles | Metrics

Select

Optimization Method of Power Supply Capacity of Distribution Network Considering Participation of Power Sales Companies in Spot Power Trading ZHAO Qingsong, XU Jianyuan Hunan Electric Power    2023, 43 (4): 95-101.   DOI: 10.3969/j.issn.1008-0198.2023.04.014 Abstract （32）      PDF（pc） （3467KB）（70）       Knowledge map    Save As an important part of the electricity trading market, the power sales companies can change the flow distribution of the distribution network by purchasing electricity from the market or delivering electricity to the market and users, thereby affecting the power supply capacity of the distribution network. Previous studies have rarely considered the impact of the uncertainty of power market trading on the operation of distribution networks when analyzing the power supply capacity of distribution networks. Based on the dual role of power sales companies, this paper first analyzes the interaction between market trading and distribution network power supply capacity. Secondly, considering the internal controllable distributed generation and controllable load participating demand-side response within the distribution network, a double-layer optimization model for distribution network power supply capacity considering power sales companies participating in electricity market spot trading is established, and it is solved based on the improved repetitive power flow algorithm and the original dual interior point method. Finally, the improved IEEE 33 test system is used to verify the algorithm, and the results show that power sales company participates in the power transaction by flexibly adjusting the power purchase and sale strategy, which not only ensures the profit but also improves the power supply capacity of the distribution net-work. This research can provide a theoretical basis for optimizing the configuration of the power market and improving the power supply capacity of the distribution network. Reference | Related Articles | Metrics

Select

Review on Non-Contact Voltage/Electric Field Sensors KE Kun, YANG Qing, QIU Zhenhui, LIAO Wei, ZHOU Jianglin Hunan Electric Power    2023, 43 (5): 71-78.   DOI: 10.3969/j.issn.1008- 0198.2023.05.011 Abstract （61）      PDF（pc） （9478KB）（69）       Knowledge map    Save Safe and accurate acquisition of electrical parameter data of the power system can ensure the safe and stable operation of the power system. Compared with traditional voltage measurement, non-contact measurement technology has higher safety because it does not need to have a direct electrical connection with the primary equipment, and has the characteristics of small size, frequency bandwidth, and good transient response characteristics, which can meet the needs of modern power grid distributed sensor networks. This paper introduces in detail the technologies of coupling capacitive voltage sensing, voltage sensing based on current integration method, D-dot electric field sensing, electric field sensing based on electro-optical effect, piezoelectric effect, and electrostatic induction effect, analyzes the advantages and existing problems of the above sensing technology, and introduces the method of electric field inversion voltage. Finally, the development prospect of non-contact voltage/electric field sensing technology is prospected. Reference | Related Articles | Metrics

Select

Research on Distortion Correction Method of Aerial Photovoltaic Module Images WANG Jiawen, ZHU Yongcan, WANG Shuai, LI Kefeng Hunan Electric Power    2023, 43 (4): 74-79.   DOI: 10.3969/j.issn.1008-0198.2023.04.010 Abstract （67）      PDF（pc） （3609KB）（68）       Knowledge map    Save Aerial photography of photovoltaic components often suffers from distortion due to shooting angle issues, which affects the measurement, recognition, and classification of elements like straight lines, angles, and proportions. To address this problem, this paper proposes an undistorted aerial photovoltaic component image correction method that requires no calibration. The approach first extracts four critical feature points from the photovoltaic component image using a feature point extraction algorithm and then matches them using a feature point matching algorithm to obtain their corresponding relationships before and after distortion. Secondly, the theoretical principles of computational geometry are utilized to compute the parameters T necessary for distortion correction through triangulation and coordinate transformation of the corresponding points. Finally, distortion correction is carried out on the image using parameter T to obtain the corrected photovoltaic component image. This algorithm not only improves the visual correction effect of the image but also increases the accuracy of data by 20%~55%.This method has a high application value in the foreign object recognition, operation and maintenance of the aerial photovoltaics module image. Reference | Related Articles | Metrics

Select

Vibration Characteristics Analysis and Optimal Design of Oil-Immersed Transformer Based on Finite Element Method YUAN Fating, YAN Zhiwei, CAO Hao, JI Ruiqing, TANG Bo Hunan Electric Power    2024, 44 (1): 11-17.   DOI: 10.3969/j.issn.1008-0198.2024.01.002 Abstract （41）      PDF（pc） （3379KB）（68）       Knowledge map    Save According to the electrical and structural parameters of the oil-immersed transformer, the circuit magnetic field simulation model is established based on the finite element simulation software. Based on the experimental measurement results and the characteristic parameters identified by J-A hysteresis model, the magnetic property model of the material is obtained. The simulation model of transformer magnetic field-structure field is established to obtain the distribution of magnetic field and stress around the transformer. Taking the calculated core Maxwell force, magnetostrictive force and winding Lorentz force as excitation, the transformer vibration displacement considering the magnetic properties of the material is calculated. The vibration displacements at different positions of the core are extracted, and the distribution rules of the vibration characteristics of the core are obtained. On this basis, in order to reduce the vibration of the oil-immersed transformer, the finite element method is combined with the time-experimental design method, and the optimal parameters are obtained by adjusting the winding parameters of the transformer. The results show that the maximum vibration displacement of the transformer before and after optimization is 6.12 μm and 5.71 μm respectively, and the optimization method significantly reduces the vibration of the transformer, which has important guiding significance for the vibration and noise reduction of oil-immersed transformer. Reference | Related Articles | Metrics

Select

Strategy of An Improved Adaptive Sliding Mode Controlling Virtual Synchronous Generator Control Based on Direct-Driven Permanent Magnet Wind Power System CHEN Anping, HU Xiaolin, LUO Zhaoxu, CHENG Zhun Hunan Electric Power    2023, 43 (4): 63-73.   DOI: 10.3969/j.issn.1008-0198.2023.04.009 Abstract （59）      PDF（pc） （5028KB）（67）       Knowledge map    Save For the direct-drive permanent magnet synchronous wind generator system, because of the difference of equivalent output impedance between inverters and transmission line impedance, the problems of multi-inverters controlled by traditional virtual synchronous generator (VSG) , such as unequal power distribution and poor circulating current suppression are presented,and an improved adaptive sliding mode control strategy is proposed for multiple VSG power sharing and circulation suppression. The given power calculating is calculated according to the total load capacity and the capacity of each inverter, and the virtual impedance according to the given reactive power to compensate the voltage drop caused by the difference of line impedance is adjusted .The sliding mode control of two VSG is designed in coordinate system, and the sliding mode surface is designed based on the difference between the inverter output voltage and the VSG reference voltage, based on Lyapunov stability theory, an adaptive sliding mode controller is designed, which consists of equivalent control, switching control and adaptive compensation. Compared with the traditional control method, the proposed control strategy power sharing and circulation suppression are achieved , and the distribution accuracy of reactive power and VSG output voltage are improved. Finally, the correctness and validity of the control strategy are verified in MATLAB/Simulink. Reference | Related Articles | Metrics

Select

Research on Grounding Grid Corrosion Diagnosis Based on Electromagnetic Field Theory and Earth Surface Potential CHU Xu, YU Shaoshuai, YAN Yabing, LI Hui Hunan Electric Power    2023, 43 (4): 118-124.   DOI: 10.3969/j.issn.1008-0198.2023.04.018 Abstract （49）      PDF（pc） （6036KB）（64）       Knowledge map    Save Because of its large scale, complex structure and strong electromagnetic interference, the grounding grid of the substation has the problems of difficult detection and large error in corrosion diagnosis. Aiming at these problems,this article proposes a method based on the combination of electromagnetic field theory (EFT) and earth surface potential (ESP) to diagnose the corrosion conductor of grounding grid,so as to make up for the defect of poor measurement accuracy of EFT method under strong magnetic interference. This method first analyzes the magnetic induction intensity distribution of the corroded conductor on the basis of EFT. Then the paper analyzes the ESP distribution of the corroded conductor, combines the magnetic induction intensity curve with the ESP distribution curve, and finally determines the location and type of conductor corrosion. The test shows that the position of the corroded conductor obtained by this method is consistent with the position of the set corroded conductor, which shows the accuracy of the method in diagnosing the corroded conductor. Reference | Related Articles | Metrics

Select

Study and Optimization on Heat Transfer Performance of Symmetric Inclined Fin Reinforcement Plate Radiator WU Youran, SHI Chunyu, LIU Wei, ZHANG Xuewei, LIU Zhichun Hunan Electric Power    2023, 43 (5): 92-98.   DOI: 10.3969/j.issn.1008- 0198.2023.05.014 Abstract （27）      PDF（pc） （11305KB）（60）       Knowledge map    Save A numerical study is carried out on the rectangular air passage between adjacent fins in the chip radiator of a large oil-immersed transformer, and the length Lf and height Hf of the symmetric diagonal ribs are taken as structural parameters to control the shape of the diagonal ribs. The numerical results show that Lf and Hf have a synergistic effect on increasing Nusselt number (Nu)of rectangular channel, while Hf has a stronger influence on friction coefficient f of rectangular channel. The proxy model between the objective performance and design parameters of rectangular channel is established by Kriging model. Finally, the optimal parameter combination is obtained by multi-objective optimization algorithm. Under this parameter combination, the Nu of rectangular channel is increased to 2.26 times, the f is increased to 3.39 times, and the comprehensive heat transfer performance index is 1.52. Reference | Related Articles | Metrics

Select

Finite Element Simulation of Abrasive Wear Characteristics for a Ring Chain Line Fitting ZENG Ping, LIU Zhigang, HUANG Changyong, LUO Fangxu, ZHANG Huapeng, CAI Xinjing Hunan Electric Power    2023, 43 (4): 90-94.   DOI: 10.3969/j.issn.1008-0198.2023.04.013 Abstract （48）      PDF（pc） （2927KB）（60）       Knowledge map    Save Electric power fittings located in the strong wind area are prone to abrasive wear. In order to study abrasive wear mechanism of electric power fittings, the wear process of a ring chain line fitting is simulated based on the finite element method. It is indicated that the maximum stress of the U-shaped ring is 692.2 MPa, far exceeding the yield strength of 45# steel which is equal to 355 MPa. After 1 400 times of abrasive wear, a negative strain along the Z-axis is shown on the contact area of the U-shaped ring, and plastic deformation outward in both the X and Y directions is observed. The wear rate of U-shaped ring makes a cycle that repeats itself from large to small and then from small to large. Reference | Related Articles | Metrics

Select

Collaborative Control Strategy of Hydropower and Stored Energy to Promote AGC Response Time Performance of Frequency Regulation Hydropower Plant SAN Meiying, YAO Yangyang, QIU Yaming, QIN Huihui Hunan Electric Power    2023, 43 (6): 93-98.   DOI: 10.3969/j.issn.1008-0198.2023.06.014 Abstract （30）      PDF（pc） （6327KB）（60）       Knowledge map    Save Northwest Power Grid is the regional power grid with the highest proportion of new energy installed capacity. Its “Two Articles” require that the AGC response time of hydropower units should be less than 10s. The AGC response time assessment of frequency regulation hydropower stations in the region is pretty severe. Based on the first frequency regulation hydropower power plant of Northwest Grid, the assessment and operational characteristics are analyzed. In addition, a suitable energy storage configuration scheme is proposed. Collaborative control strategy of hydropower and stored energy to promote the AGC response time performance is analyzed. The stored energy link is switched through electric break to regulate operation conditions whose AGC response time is less than 17s. Modeling and simulation are performed on Simulink platform,moreover economic analysis is carried out under hypothetical boundary conditions. The results show that through water storage collaboration, the AGC response time performance has been significantly optimized. Calculated based on a monthly reduction of 440 points, the internal rate of return reaches 18.7%, which can effectively alleviate the severe situation of AGC response time assessment in power plants and improve the economic benefits of power plants. Reference | Related Articles | Metrics

Select

Neural Network Prediction Methods of Short-Term Peak Load Based on Multi-Information Fusion XU Shunkai, ZHU Jiran, TANG Haiguo, DENG Wei, HUANG Zhao, ZOU Changchun Hunan Electric Power    2024, 44 (1): 38-44.   DOI: 10.3969/j.issn.1008-0198.2024.01.006 Abstract （33）      PDF（pc） （5643KB）（59）       Knowledge map    Save In order to reduce the complexity of load data and improve prediction accuracy, an neural network model based on multi information fusion for short-term peak load is proposed on this article. The Pearson correlation coefficient is selected to analyze the closeness between weather information such as holidays, temperature, and humidity. In proposed model considering the key weather information fusion, the input load parameters is optimized,a new dataset of the neural network model is reconstructed, and overfitting of the neural networkis avoided,and the accuracy of short-term peak load prediction is improved. A simulation example of peak load forecasting proves that the proposed method is more effective in improving the accuracy of short-term peak load forecasting compared to the single enhanced decision tree model and neural network model that do not consider multiple information fusion. Reference | Related Articles | Metrics

Select

Case Analysis and Application of Waste Oil Disposal in Transformer REN Qiaolin, ZHANG Yi, ZHANG Wei, CAI Xuan, WU You, LI Zhongling Hunan Electric Power    2023, 43 (4): 114-117.   DOI: 10.3969/j.issn.1008-0198.2023.04.017 Abstract （73）      PDF（pc） （1358KB）（56）       Knowledge map    Save Taking the waste oil treatment of a power supply company as an example, the Meyers index classification and differentiation treatment of oil products are introduced, it not only reduces environmental pollution, but also extends the life cycle of transformer oil, saves the cost of oil treatment and new oil purchase, and promotes the utilization of renewable resources. Reference | Related Articles | Metrics

Select

Research on Detection Circuit and Method of Ground Insulation Impedance for Photovoltaic Array LI Jiong, JIANG Li, NING Guangfu, WU Jinbo, HE Zhiqiang Hunan Electric Power    2023, 43 (5): 11-15.   DOI: 10.3969/j.issn.1008- 0198.2023.05.002 Abstract （64）      PDF（pc） （3919KB）（56）       Knowledge map    Save This paper proposes a detection circuit and method of insulation impedance for photovoltaic array, which contains a voltage sampling circuit of photovoltaic negative electrode to the earth, two electronic switches and three balance resistors. In order to balance the sampling resistance, a balance resistor equivalent to the resistance of the voltage sampling branch is always connected in parallel between the positive electrode of the photovoltaic panel and the earth, so that the voltage of the sampling point between the negative electrode of the photovoltaic panel and the earth will not be extremely small when the insulation performance is normal, which reduces the requirements for voltage sampling accuracy. The branch consisting of an electronic switch and a resistor in series is connected between the positive/negative electrodes of the photovoltaic panel and the earth, and the resistor in series is equivalent to the critical insulation impedance that meets the leakage current standard. When the impedance of one electrode of the photovoltaic panel decreases, the other pole electronic switch is closed connected in parallel with the other electrode, and the corresponding balance resistor is connected to improve the sensitivity of the sampling voltage to the impedance change of the circuit, so as to calculate the actual impedance of the circuit. The proposed method can obtain accurate insulation impedance with low-precision voltage sampling, which improves the reliability of detection. Reference | Related Articles | Metrics

Select

Governance Method of Power Quality in New Power Distribution Area Based on Energy Storage System LAN Zheng, YIN Rui, ZOU Bin, HE Dong Hunan Electric Power    2023, 43 (4): 56-62.   DOI: 10.3969/j.issn.1008-0198.2023.04.008 Abstract （55）      PDF（pc） （3308KB）（54）       Knowledge map    Save In the new power distribution area, due to the wide application of power electronic devices and the access of a large number of distributed energy sources, the power quality of the new power distribution area is seriously affected and the power fluctuation is caused. In order to improve the power quality and power fluctuation of the new power distribution area, a new power quality management method based on energy storage system is proposed. This method can improve the comprehensive adjusting ability of the energy storage system at the head of the area. It can not only control the current harmonics, reactive power and unbalance current of the new power distribution area, but also stabilize the active power effectively. Firstly, the structure of the new power distribution area and the topology of the energy storage system are introduced, and the mathematical model is built. Then, in the harmonic detection section of the control section, the four-wire ip-iq harmonic detection method based on moving mean filter is adopted. And in the process of energy storage power adjustment, the strategy of battery charging and discharging considering energy storage capacity is adopted. At the same time, the command current is accurately tracked by repetitive control and PI control. Finally, the simulation results show that the proposed energy storage system and its control strategy can not only effectively improve the power quality of the new power distribution area, but also smooth the active power fluctuation. Reference | Related Articles | Metrics

Select

Accurate Classification Method of Power Customers Based on Jieba Chinese Word Segmentation GAO Pan, LI Fei, PENG Yuanhao, ZHANG Canhui, PENG Haijun Hunan Electric Power    2023, 43 (5): 151-154.   DOI: 10.3969/j.issn.1008- 0198.2023.05.022 Abstract （51）      PDF（pc） （3356KB）（52）       Knowledge map    Save Aiming at the customer segmentation in the basic data of electric power marketing, an innovative method is proposed to achieve accurate classification of major customers based on jieba Chinese word segmentation. A self-defined dictionary containing the basic categories of customers is constructed, and jieba is used to complete the segmentation of the text data. The classification feature database is built based on the classification rules of high-frequency words and keywords in the word segmentation results. The classification feature database is used as the input of the neural network pre-training model to train the neural network model of customer classification, and the accurate classification results of power customers are finally output. This method solves the problem of unclear user category or too complicated classification method in the current power system database and provides the basis for the power company to develop differentiated customer service. Reference | Related Articles | Metrics

Select

Maximum Power Tracking of Wind Power Generation System Based on Improved Nonsingular Fast Terminal Sliding Mode Inversion Control LI Shengqing, CHEN Xin, WEN Yanxi, YAO Hongde, DENG Na Hunan Electric Power    2023, 43 (5): 109-115.   DOI: 10.3969/j.issn.1008- 0198.2023.05.016 Abstract （45）      PDF（pc） （6582KB）（50）       Knowledge map    Save To address the problems of non-linearity, uncertainty of system parameters and external disturbances in maximum power tracking of permanent magnet direct-drive wind turbine systems,a non-singular fast terminal sliding mode inversion control strategy based on a finite-time disturbance observer is proposed. For the speed tracking problem, the system parameter uncertainty and external disturbances are defined as set-total disturbances, which are compensated after fast and accurate estimation by the observer. The inverse control method is used to deal with the nonlinear system, and the virtual control law is designed in combination with the dynamic surface control, while the sliding mode control law is designed to improve the convergence speed and tracking accuracy of the system. The stability and effectiveness of the system are demonstrated by Lyapunov theory and simulation experiments. Reference | Related Articles | Metrics

Select

Hunan Electric Power    2023, 43 (5): 1-2.   Abstract （50）      PDF（pc） （1436KB）（50）       Knowledge map    Save Related Articles | Metrics

Select

Optimization Strategy of Electric Vehicle Charging Load Based on Stage-Sharing Tariff Response XU Wenzhe, FANG Baling, ZHANG Qifei, LI Wei, LIU Hao Hunan Electric Power    2024, 44 (1): 94-100.   DOI: 10.3969/j.issn.1008-0198.2024.01.013 Abstract （40）      PDF（pc） （2363KB）（50）       Knowledge map    Save Aiming at the charging load optimization problem of electric vehicles, this paper proposes a charging load optimization strategy for electric vehicles based on stage-sharing tariff response. The strategy establishes an electric vehicle charging load model and simulates the load variation of uncontrolled charging of electric vehicles by Monte Carlo algorithm, taking into account the electric vehicle load factor. On the basis of the elasticity matrix of peak-valley leveling tariffs, the stage time-sharing tariff model is established by subdividing different equal time periods, and the optimization model of time-sharing tariffs for electric vehicles is constructed with the optimization objectives of minimizing the mean square deviation of the total charging costs of the users and the total load of the system, and the improved chaotic multi-objective genetic algorithm is used to solve and optimize the model. Finally, the effectiveness and economy of the strategy are verified by the experimental comparison results, where the total user charging cost and the total system load mean squared deviation are reduced by 4091 yuan and 37.151 MW respectively, compared with the traditional time-sharing tariff scheme under the given data conditions. Reference | Related Articles | Metrics

Select

Discontinuous Modulation for a Quasi-Z-Source Inverter With Low Switching Times and High Voltage Gain YI Wenjing, CAO Kun, MENG Yuwei, LUO Zhaoxu, CHENG Zhun Hunan Electric Power    2023, 43 (5): 61-70.   DOI: 10.3969/j.issn.1008- 0198.2023.05.010 Abstract （74）      PDF（pc） （16347KB）（49）       Knowledge map    Save The quasi-Z-source inverter is widely used to replace traditional two-stage structures due to its advantages of continuous input current and simple structure. Aiming at the problems of complex gate signals generation, excessive switching times of inverter switches, high switching losses, and insufficient voltage gain in the existing modulation strategies, a discontinuous modulation for quasi-Z-source inverter with low switching times and high voltage gain is proposed, which uses fewer reference signals to generate gate signals. At the same time, the switching signals of this discontinuous modulation strategy are clamped to positive or negative pole, which significantly reduces the switching times of the inverter, thereby reducing the switching losses of the switches. In addition, the shoot-through duration and the insertion position are reasonably planned to achieve the greatest voltage gain. The correctness and effectiveness of the modulation strategy are verified by MATLAB/PLECS simulation analysis and RT-LAB experimental results. Reference | Related Articles | Metrics

Select

Bidirectional AC-DC Power Supply Topology and It's Modulation for Mobile V2N Device QIU Wenhui, QU Yaohui, SU Mei, LI Jinliang, WAN Dai, XU Guo Hunan Electric Power    2023, 43 (5): 55-60.   DOI: 10.3969/j.issn.1008- 0198.2023.05.009 Abstract （36）      PDF（pc） （10901KB）（47）       Knowledge map    Save For the active support application requirements of new energy grid connection, a two-stage structure consisting of a three-phase full bridge AC-DC converter and a dual active bridge (DAB) converter is selected as the research object. Under the influence of parasitic capacitance of devices, DAB converters will face the problem of difficulty in achieving soft switching, and in wide voltage range applications, traditional extended phase shift (EPS) control will bring significant reactive power circulation problems when it is far from the unit voltage gain point. Therefore, a topology structure and its modulation method are proposed, which injects additional excitation current by adding an excitation inductor to ensure the full load range soft switching of the DAB converter. At the same time, traditional EPS control is improved to ensure efficient energy transmission over a wide voltage range. Finally, an experimental prototype of a 20kW all SiC device is built to conduct steady-state testing and soft switching performance testing on the device, verifying the effectiveness of the proposed method. Reference | Related Articles | Metrics

Select

A Dual Mode Photovoltaic Maximum Power Point Tracking Algorithm Based on Partial Shading Detection ZUO Xiaoyun, LUO Zhenzhen, LIU Hongyi Hunan Electric Power    2023, 43 (5): 43-48.   DOI: 10.3969/j.issn.1008- 0198.2023.05.007 Abstract （42）      PDF（pc） （8195KB）（47）       Knowledge map    Save Photovoltaic power generation as an important component of a new type of power electronic system,has random fluctuations.And how to improve its power supply efficiency and reliability becomes a challenging problem.For this reason, this paper proposes a dual-mode maximum power point tracking (MPPT) algorithm based on partial shading detection. The photovoltaic power prediction model based on long short-term memory neural network (LSTM) is used to detect partial shading conditions. On this basis, the proposed dual-mode MPPT algorithm considers both normal system operation and localized shading conditions. Based on radial basis function neural network (RBFNN), MPPT algorithm under partial shading is implemented, while the traditional perturbation observation method is used to implement MPPT algorithm under normal operation conditions. In order to validate the effectiveness of the proposed MPPT method, a PV system model is built and the performance of the proposed algorithm is analyzed for different operating conditions in the MATLAB/Simulink environment. Reference | Related Articles | Metrics

Select

Ahead Optimal Dispatch of Multi Energy Power System Considering Power Flexibility and Complementarity XIAO Bai, ZHANG Bo Hunan Electric Power    2023, 43 (4): 16-23.   DOI: 10.3969/j.issn.1008-0198.2023.04.003 Abstract （51）      PDF（pc） （3056KB）（46）       Knowledge map    Save A multi energy power system day ahead optimization scheduling method considering power flexibility and complementarity is proposed to address the volatility and intermittency of wind and photovoltaic power generation, as well as the coordinated and optimized operation of multi energy power systems. Firstly, a supply and demand model for power flexibility and complementarity is established. Then, a multi-objective coordinated hierarchical optimization scheduling model for wind power, solar power, hydroenergy, gas energy, and thermal power,energy storage storage is constructed with the optimization objectives of optimizing the economy and stability of thermal power operation, and minimizing the total pollutant emissions. Renewable energy complementary power sources and complementary power demand indicators are defined, and the aggregation ratio of renewable energy complementary power sources is determined to minimize the complementary power demand indicators. Finally, the artificial bee colony algorithm is improved by introducing dynamic probability and developing the optimal guidance strategy for the bee colony, and the improved artificial bee colony algorithm is used to solve the established optimization scheduling model. The numerical results show that the proposed model and algorithm are feasible for the multi energy complementary coordinated scheduling problem. Reference | Related Articles | Metrics

Select

Research on Multi-Objective Optimal Control of Virual Synchronous Generator Inverter in Unbalanced Power Grid Based on Wolf Pack Algorithm ZHU Hongping, ZHU Hongzhi, QIAN Wanming, GUO Liwen, HAN Yinglong Hunan Electric Power    2023, 43 (4): 40-47.   DOI: 10.3969/j.issn.1008-0198.2023.04.006 Abstract （49）      PDF（pc） （3980KB）（45）       Knowledge map    Save This paper presents a multi-objective coordinated optimal control of virtual synchronous generator(VSG)inverter based on wolf swarn algorithm to address the issues of unbalanced grid connected output current and fluctuations in active and reactive power when the grid voltage is unbalanced.For the current balance, suppression of active and reactive power fluctuations between the contradictions,a multi-objective optimization control is designed, introducing adjustment coefficients and imbalance, and establishing a unified expression for negative sequence reference current and a multi-objective optimization function. And through the wolf swarm algorithm, the multi-objective function is optimized to achieve coordinated control among the three controls, improving the output power quality of the VSG inverter. Finally, the proposed control method is simulated to verify its feasibility and effectiveness. Reference | Related Articles | Metrics

Select

Study on Composition Change Rule of Composite Insulator Silicone Rubber During Aging Process NING Kai, JIANG Zhenglong, FU Zhiyao Hunan Electric Power    2023, 43 (6): 11-14.   DOI: 10.3969/j.issn.1008-0198.2023.06.003 Abstract （31）      PDF（pc） （5926KB）（45）       Knowledge map    Save In order to study the variation rule of components in silicone rubber of composite insulators during aging process, various tests are conducted on unused silicone rubber as well as silicone rubber used for 2, 6 and 10 years. These tests includ scanning electron microscopy analysis, thermogravimetric analysis, differential scanning calorimetry analysis, Fourier transform infrared analysis, and X-ray spectroscopy analysis. The relevant results show that during operation, the integrity of silicone rubber molecular chains deteriorates, and more and more cracks and voids appear on the surface of silicone rubber. Additionally, the operation of silicone rubber is closely related to the variation and precipitation of aluminum hydroxide in its components, with aluminum hydroxide experiencing the most significant changes during operation. This study can better reflect the surface aging status of silicone rubber and is of great significance for the formulation design and aging failure analysis of composite insulators. Reference | Related Articles | Metrics

Select

Comparison Research on Local Velocity Measurement Techniques for Liquid Metal XIAO Hui, LIU Zhichun, WANG Suhao, ZHANG Xianjun, LAN Zhike, ZHUO Wenbin, WANG Sheng Hunan Electric Power    2023, 43 (5): 134-143.   DOI: 10.3969/j.issn.1008- 0198.2023.05.020 Abstract （36）      PDF（pc） （12577KB）（43）       Knowledge map    Save The flow field affects the flow rate, temperature, oxygen concentration and stress distribution in key equipment of energy system. Obtaining accurate flow field distribution can help improve the structural design ability and system operation reliability. In order to select suitable methods for measuring flow field in liquid metal cooled reactor of advanced nuclear energy system, it is reviewed the suitable measurement techniques for local flow velocity of liquid metal. And the research progress as well as advantages and disadvantages of different measurement techniques are compared. It is found that there are no mature metal flow field measuring instruments for engineering application at present. As for the invasive method, the technology maturity of pitot tube, electromagnetic probe, and eddy current flowmeter probe is relatively high. As for the non-invasive method, the maturity of ultrasonic doppler velocimetry is the highest while the contactless inductive flow tomography is better in application prospects. On this basis, measurement techniques are recommended for typical operating situations in nuclear reactors, among which the contactless inductive method has wider applicability due to its nature of no added particles and high time resolution. Reference | Related Articles | Metrics

Select

Research on High Precision Meteorology and Hydrological Condition Monitoring and Forcasting System in Small Watershed ZHANG Hongqiang, ZHANG Jun, XIAO Jianhong, YUAN Kaiyi, TIAN Haiping Hunan Electric Power    2023, 43 (5): 38-42.   DOI: 10.3969/j.issn.1008- 0198.2023.05.006 Abstract （34）      PDF（pc） （8744KB）（42）       Knowledge map    Save In view of the remote small watershed with lack of meteorological data, a high-precision meteorological and hydrological condition monitoring and forecasting system for small watersheds is established using remote sensing technology. This system supplements the meteorological data in small watersheds and provides data support for the development of related models such as meteorological forecasts and rainfall-runoff models, so as to fully exert the advantageous position of small hydropower in the power grid and increase the space for new energy consumption. Reference | Related Articles | Metrics

Select

Research on Coordination and Optimization of Large Scale Electric Vehicles Connected to Microgrid Using Improved Symbiotic Organisms Search Algorithm KANG Tong, ZHU Jiran, TANG Haiguo, ZHOU Hengyi, ZHOU Kehui Hunan Electric Power    2023, 43 (5): 144-150.   DOI: 10.3969/j.issn.1008- 0198.2023.05.21 Abstract （46）      PDF（pc） （6636KB）（40）       Knowledge map    Save Aiming at the optimization and coordination operation of electric vehicles connected to microgrid, the architecture, operation mode, output characteristics and mathematical model of microgrid including electric vehicles are analyzed , and the disorderly charging load model of electric vehicles is established by using Monte Carlo method. An objective function is established to minimize the comprehensive cost and peak-valley difference of microgrid. To solve the complex, high-dimensional and model and enhance the performance of original symbiotic organisms search algorithm(SOS), a novel improved symbiotic organisms search algorithm algorithm(ImSOS)is proposed. In ImSOS, a quasi-reflection-based learning scheme is employed in the population initialization step of original SOS. Moreover, the strategy of the modifications of benefit factors is used in the mutualism phase of SOS. A strategy of narrowing the search range of randomly generated coefficients is adopted in the commensalism phase of SOS. Finally, by setting up scenarios of disordered charging and coordinated optimized operation of electric vehicles, the output comprehensive operating cost and peak-valley difference in microgrid are compared. The result presents the scientificity and effectiveness of the method proposed in this paper. Reference | Related Articles | Metrics

Select

Design and Simulation of Power Supply-Traction-Hybrid Energy Storage System for Urban Rail Trains ZHU Zhiqiang, WANG Xin, QIN Bin Hunan Electric Power    2024, 44 (1): 24-31.   DOI: 10.3969/j.issn.1008-0198.2024.01.004 Abstract （65）      PDF（pc） （7016KB）（40）       Knowledge map    Save In order to further improve the recovery and utilization efficiency of urban rail train regenerative braking energy, a structure of urban rail train traction power supply system based on distributed ground hybrid energy storage is designed through the analysis of system functional requirements, and the power supply network, train traction and energy storage system models are established. Moreover, aiming at the problem that low pass filtering leads to a large amount of power exchange between lithium batteries and supercapacitors, a stepped power allocation method with supercapacitor compensation is proposed.This method has small computation and strong real-time performance,and can avoid the internal power circulation of the hybrid energy storage system. Combined with the proposed model and strategy, MATLAB Simulink is used to simulate.The results validate that the energy utilization efficiency of the hybrid energy storage system is improved by 1.39%, the voltage regulation rate is increased by 12.75% and the energy saving rate is increased by 6.72%. Reference | Related Articles | Metrics